What do you think of my routine?

[Flexor]

As far as the skullcrushers go, I'm very comfortable with them--they're one of my favorite exercises.

Then that is the last reason to drop them. They are an excellent single joint mass building exercise. You can't use as much weight in overhead extensions, stick to skulls.

As for 5 days in a row, that is too much for the CNS, and that could lead to slower growth gains. More than 2 days in a row is too much. You just need a rest day in the middle, on wednesday, so try shifting around your days with what you are comfortable with.